Why do the bridges
look like they do?

Who designed
the bridges?

Tacoma Narrows Bridge Lesson Plans
Science Lab Activity

Construction of 1940 and Reconstruction in 1950

The purpose of this lab activity is to introduce the challenges
of building a suspension bridge. Students will explore the engineering
challenges of building the new Tacoma Narrows Bridge in 1950.

Lesson Objectives

As a result of this lesson, students will be able
to:

Develop an understanding of the design constraints engineers
encounter when building a bridge

Begin to understand the important of planning before building
their bridge especially when supplies are limited.

Materials Needed:

8 feet of string per group, a roll of masking tape, a cardboard
box, pencil, scissors, pop-sickle sticks, sand or clay, books,
and a piece of paper.

Lesson Steps

1. Students will break up into groups
of four.

2.Each group
will obtain their materials.

3. The group must construct a suspension bridge
across two stacks of books with the materials listed above.

4. The group must sketch the bridge they
built.

5. After the sketch is complete, the
group will use the Narrows Bridge web site illustration of basic
suspension bridge parts to label their drawing with the different
parts of a typical suspension bridge.

6. The group will measure the following
in inches:

Length of bridge

Length of center span

Height of towers from bottom to top

Width of deck on the bridge

Rules:

You may not talk to the group across from you.

You cannot use any more material than what was given to you.

Record any design changes you make when building your bridge
and explain why this was necessary.

Post-Lab Activity:

The students should
describe what they observed during this activity as well as some
principles of physics. The similarities between engineering a bridge
and building their model bridge will be noted.

Relating Mathematics:

Use the following
measurements of the current Tacoma Narrows Bridge to have the students
compare the measurements of their bridge to the real bridge. Incorporate
scale factor. The
Bridge Machine Since 1950 has “Span Statistics”
that could be used in the classroom for fun facts: